“Shewglie House” is a private property located approximately 6 miles west of Drumnadrochit, Inverness. In the late months of 2010 Raeburn Drilling were contracted to construct 10 geothermal boreholes to a depth of 100 meters.
Using one of our tractor mounted drilling rigs, our drillers drilled through approximately 30 meters of sand and gravel deposits before reaching bedrock. The holes were then drilled to a depth of 100 meters, drilling through deposits of basalt (a common extrusive volcanic rock).
A 40mm diameter polyethylene geothermal loop was then installed and the borehole was backfilled with a thermally enhanced grout mix. The grout is made up of bentonite (a natural clay mineral) and fine sand. It’s role is to provide a thermally conductive interface between the bedrock and the geothermal loop. It will also prevent entry of surface water into the borehole.
After the loops were installed quality checks were performed to ensure the integrity of the loops under pressure and unobstructed flow through the loop.
Some 6 months later Raeburn were contracted to install the pipe-work connecting the ground loops to the heat exchanger. Pipework from the ground loops was initially laid to a manifold chamber, larger diameter pipes were then laid from the manifolds to the heat exchanger.
Fusion welded joints were used to provide long term, leak free connections and the buried pipework was fitted with insulating foam to minimize heat loss during the process.
Each geothermal loop was flushed before being connected to the manifold. All of the loops were then connected to the manifold and the complete system was flushed as a whole. Following this, a full system pressure test was carried out.
The main contractor on the site was O’Brien Construction Ltd. Raeburn Drilling were employed by O’Brien to complete the drilling works, later to be contracted by Korrie Mechanical & Plumbing Ltd to carry out the header works.